Resolution of refractory no-reflow with intracoronary epinephrine

Intracoronary adenosine compared with adrenaline and verapamil in the treatment of no-reflow phenomenon following primary PCI in STEMI patients

BACKGROUND

no-reflow can complicate up to 25% of pPCI and is associated with significant morbidity and mortality. We aimed to compare the outcomes of intracoronary epinephrine and verapamil with intracoronary adenosine in the treatment of no-reflow after primary percutaneous coronary intervention (pPCI).

METHODS

108 STEMI patients had no-reflow during pPCI were assigned into four groups. Group 1, in which epinephrine and verapamil were injected through a well-cannulated guiding catheter. Group 2, in which same drugs were injected in the distal coronary bed through a microcatheter or perfusion catheter. Group 3, in which adenosine was injected through a guiding catheter. Group 4, in which adenosine was injected in distal coronary bed. Primary end point was the achievement of TIMI III flow and MBG II or III. Secondary end point was major adverse cardiovascular and cerebrovascular events (MACCEs) during hospital stay.

RESULTS

The study groups did not differ in their baseline characteristics. Primary end point was achieved in 15 (27.8%) patients in the guide-delivery arm compared with 34 (63%) patients in the local-delivery arm, p < 0.01. However, the primary end point did not differ between the epinephrine/verapamil group and the adenosine group (27 (50%) vs 22 (40.7%), p = 0.334). The secondary end points were similar between the study groups.

CONCLUSION

Local delivery of epinephrine, verapamil and adenosine in the distal coronary bed is more effective in achieving TIMI III flow with MBG II or III compared with their guide-delivery in patients who suffered no-reflow during pPCI. There was no difference between epinephrine/verapamil Vs. adenosine.

Role of Intracoronary Adrenaline in the Treatment of No-Reflow Phenomenon in Patients Undergoing Percutaneous Coronary Intervention

The no-reflow phenomenon is defined as the failure to restore coronary flow demonstrated by the reduced or missing flow in angiography despite the patent artery. There are pharmacological strategies proposed and studied to manage the no-reflow phenomenon. The medication groups used are purine nucleoside (adenosine), calcium channel blockers (verapamil, nicardipine), beta 2 receptor agonists (adrenaline, nitroprusside), fibrinolytic agents (streptokinase, tissue plasminogen activators), glycoprotein IIb/IIIa inhibitors (abciximab, tirofiban). We present a case of a woman hospitalized in non-ST elevation myocardial infarction (NSTEMI) conditions. The patient underwent coronary angiography, in which a single vessel coronary artery disease (CAD); left anterior descending (LAD) stenosis of 90% was found. In this condition, the patient underwent percutaneous coronary intervention (PCI) of LAD. The no-reflow phenomenon occurred with thrombolysis in myocardial infarction (TIMI) flow grade of 0 during the procedure. As a consequence, the patient presented chest pain and important hypotension (BP of 70/45). Because of the hypotensive state of the patient, we decided to administer intracoronary (IC) adrenaline directly. In our case, we used adrenaline as a first-line treatment for the no-flow phenomenon due to the hypotensive state during the PCI procedure. Generally, we initially use IC nitrate or IC adenosine to resolve the phenomenon, and when the no-reflow persists we use IC adrenaline because of its side effects mentioned above. Anyway, we believe that in specific cases of hypotension and bradycardia, the use of adrenaline as the first line of therapy should be considered.

Development of Multi-Vessel Coronary No-Reflow Following Elective Percutaneous Intervention in One Vessel

Percutaneous coronary intervention (PCI) is a frequently performed procedure that can have minor or major complications. One of the more serious complications of PCI is the development of coronary no-reflow. No-reflow signifies reduced or absent coronary flow in the distal coronary circulation in the absence of flow-limiting lesions. We present a case of a middle-aged man who presented as an outpatient for elective coronary angiography due to angina pectoris and a high-risk exercise stress test. Coronary angiography demonstrated significant single-vessel disease with lesions in the proximal and mid-segments of the left anterior descending (LAD) coronary artery. Successful placement of drug-eluting stents in the LAD was followed by a severe drop in blood pressure, worsening chest pain, and ST elevation on telemetry. Immediate angiography showed the development of no-reflow in both the LAD and left circumflex coronary arteries. Ionotropic and intravenous anti-platelet agents were administered with simultaneous placement of an intra-aortic balloon pump, restoring normal flow in both arteries. No-reflow occurs most commonly following PCI in certain lesion subsets, and it is usually seen only in the vessel in which the PCI was performed (culprit vessel). It is important to realize that this phenomenon can occur in other circumstances since immediate recognition and treatment can be lifesaving.

"No-Reflow" Phenomenon: A Contemporary Review

Primary percutaneous angioplasty (pPCI), represents the reperfusion strategy of choice for patients with STEMI according to current international guidelines of the European Society of Cardiology. Coronary no-reflow is characterized by angiographic evidence of slow or no anterograde epicardial flow, resulting in inadequate myocardial perfusion in the absence of evidence of mechanical vessel obstruction. No reflow (NR) is related to a functional and structural alteration of the coronary microcirculation and we can list four main pathophysiological mechanisms: distal atherothrombotic embolization, ischemic damage, reperfusion injury, and individual susceptibility to microvascular damage. This review will provide a contemporary overview of the pathogenesis, diagnosis, and treatment of NR.

Intracoronary epinephrine versus adenosine in the management of refractory no-reflow phenomenon: a single-center retrospective cohort study

BACKGROUND

The no-reflow phenomenon is associated with a considerable reduction in myocardial salvage in patients with ST elevation myocardial infarction (STEMI) treated by primary percutaneous intervention (PCI). There has been no head-to-head comparison of intra-coronary epinephrine to adenosine in the management of no-reflow phenomenon.

OBJECTIVES

Evaluate the short- and long-term efficacy and safety of using intracoronary epinephrine versus adenosine for management of the catastrophic no-reflow phenomenon that may occur during primary PCI.

DESIGN

Retrospective cohort.

SETTING

Single center in Egypt.

PATIENTS AND METHODS

The study included STEMI patients who developed refractory no-reflow phenomenon during primary PCI after failure of conventional treatments and received either intracoronary epinephrine or adenosine.

MAIN OUTCOME MEASURES

No-reflow management measured through improvement of thrombolysis in myocardial infarction grade (TIMI flow), myocardial blush grade, TIMI frame count and major adverse cardiovascular events (MACE) at 1-year follow up.

SAMPLE SIZE

156 patients with refractory no-reflow phenomenon during primary PCI.

RESULTS

Successful reperfusion was achieved in 74 of 81 (91.4%) of patients who received epinephrine and in 65 of 75 (86.7%) who received adenosine (P<.05). Fifty-six of 81 patients (69.1%) achieved TIMI III flow after epinephrine administration versus 39 of 75 patients (52.7%) in the adenosine group (P=.04). The incidence of heart failure after 1 year of follow up was lower in the epinephrine group compared to the adenosine group (6.3% vs. 19.2%, P<.017). MACE after 1 year of follow up was lower in patients who received epinephrine compared to those who received adenosine (11.3 % Vs. 26.7 %, P<.01).

CONCLUSION

During primary PCI, intracoronary epinephrine is as effective as adenosine in successful management of refractory no-reflow phenomenon with a more favorable long-term prognosis compared to adenosine.

LIMITATIONS

Retrospective design.

CONFLICT OF INTEREST

None.

Intracoronary epinephrine and verapamil in the refractory no-reflow phenomenon in patients with acute myocardial infarction

Despite modern advances in performing percutaneous coronary interventions, refractory no-reflow remains a serious problem that worsens in-hospital and long-term prognosis. Low-dose adrenaline may exhibit potent beta-receptor agonist properties that mediate coronary vasodilation.

Aim. To evaluate the efficacy and safety of intracoronary administration of epinephrine and verapamil, as well as their combination, compared with standard treatment in patients with ST-segment elevation myocardial infarction (STEMI) and refractory no-reflow during percutaneous coronary interventions.

Material and methods. Patients with STEMI and refractory no-reflow will be randomized into 4 groups: standard therapy, intracoronary adrenaline, intracoronary verapamil, intracoronary epinephrine + verapamil. All patients will be assessed for epicardial blood flow using the Thrombolysis in Myocardial Infarction (TIMI) and Myocardial Blush Grade (MBG) scales, peak troponin levels, ST segment changes, echocardiography, magnetic roesnance imaging, and dynamic single photon emission computed tomography.

Results. Based on the pharmacodynamic effects of epinephrine and verapamil, their combination is expected to have a more potent vasodilating effect.

Conclusion. If the Intracoronary administration of EPInephrine and VERapamil in the refractory no-reflow phenomenon (EPIVER) study will be successful, a novel, more effective method for managing refractory no-reflow phenomenon will appear. This will ensure better preservation of left ventricular systolic function, as well as improve the prognosis and clinical course of the disease.

Comparison of Intracoronary Epinephrine and Adenosine for No-Reflow in Normotensive Patients With Acute Coronary Syndrome (COAR Trial)

Background:

Intracoronary epinephrine has been effectively used in treating refractory no-reflow, but there is a dearth of data on its use as a first-line drug in normotensive patients in comparison to the widely used adenosine.

Methods:

In this open-labeled randomized clinical trial, 201 patients with no-reflow were randomized 1:1 into intracoronary epinephrine as the treatment group and intracoronary adenosine as the control group and followed for 1 month. The primary end points were improvement in coronary flow, as assessed by TIMI (Thrombolysis in Myocardial Infarction) flow, frame counts, and myocardial blush. Secondary end points were in-hospital and short-term mortality and major adverse cardiac events.

Results:

In all, 101 patients received intracoronary epinephrine and 100 patients received adenosine. Epinephrine was generally well tolerated with no immediate table death or ventricular fibrillation. No-reflow was more effectively improved with epinephrine with final TIMI III flow (90.1% versus 78%, P=0.019) and final corrected TIMI frame count (24±8.43 versus 26.63±9.22, P=0.036). However, no significant difference was observed in final grade III myocardial blush (55.4% versus 45%, P=0.139), mean reduction of corrected TIMI frame count (−25.71±11.79 versus −26.08±11.71, P=0.825), in-hospital and short-term mortality, and major adverse cardiac events.

Conclusions:

Epinephrine is relatively safe to use in no-reflow in normotensive patients. A significantly higher frequency of post-treatment TIMI III flow grade and lower final corrected TIMI frame count with relatively better achievement of myocardial blush grade III translate into it displaying relatively better efficacy than adenosine.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04699110.

[Our enemy : the clot. Coronary thrombosis : strategy and therapeutic arsenal]

Intra coronary thrombus is  frequently encountered during acute coronary syndromes revascularisation procedures. It can also be encountered during angioplasty procedures in a stable angina context, although at a much lesser frequency.In both situations, it harbors a risk of poor angiographic result and poor prognosis. Intracoronnary thrombus may cause coronary occlusion at the angioplasty site or distal embolic  flow obstruction. Per procedure thrombus prevention rests on an prior optimal anti thrombotic treatment and in some circumstances the choice to defer the revascularisation procedure in the complex high risk setting. Treating the initiated thrombus remains controversial concerning thrombectomy and GPIIBIIIa inhibitors which are still in use in common practice. No reflow phenomenon is a particularly complex setting during cornary angioplasties, partially but not solely related to a thrombotic complication. It's treatment remains unclear in the absence of related oriented studies.The current mechanical and pharmacological antithrombotic therapies must remain common practice and used appropriately as of the clinical and angiographic setting, until further scientific outbrakes.

Comparison of the Outcomes between Coronary No-Reflow and Slow-Flow Phenomenon in Non-STEMI Patients

BACKGROUND

Coronary slow-flow phenomenon (CSFP) and coronary no-reflow phenomenon (CNP) are associated with increased risk of major cardiovascular adverse events (MACE).

OBJECTIVES

This study aimed to evaluate and compare the one-year clinical follow-up outcomes among patients with CNP and CSFP who underwent percutaneous coronary interventions (PCI) in non-ST elevation myocardial infarction (NSTEMI).

METHODS

This study included a total of 858 patients who were diagnosed with NSTEMI and underwent PCI within 24 h of symptom onset. The patients were divided into two groups, the CSFP group (n=221) and the CNP group (n=25), regarding the angiographic characteristics of thrombolysis in myocardial infarction (TIMI) flow of the infarct-related artery. Patients were followed for one-year. A p-value of <0.05 was considered significant.

RESULTS

CNP was observed in 2.91%, and CSFP was observed in 25.75% of the patients. Clinical endpoints analyzed that stroke was significantly higher in the CNP group than in the CSFP group (6 (24%) vs. 6 (2.70%), p<0.001) and MACE was significantly higher in the CNP group than in the CSFP group (11 (44%) vs. 51 (23.10%), p=0.022). Forward conditional logistic regression analysis demonstrated that body mass index (BMI) (OR=1.11, 95%CI: 1.00-1.24, p=0.038) and baseline heart rate (HR) (OR=0.923, 95%CI: 0.88-0.96, p<0.001) were the independent predictors of CNP in NSTEMI.

CONCLUSION

CNP patients have worse clinical outcomes and a higher risk of stroke compared with CSFP patients in NSTEMI. (Arq Bras Cardiol. 2021; 116(5):856-864).

Outcomes in Coronary No-Reflow Phenomenon Patients and the Relationship between Kidney Injury Molecule-1 and Coronary No-Reflow Phenomenon

Fundamento

O fenômeno de no-reflow coronário (CNP, do inglês Coronary no-reflow phenomenon) está associado a um risco aumentado de eventos cardiovasculares adversos maiores (ECAM).

Objetivo

Este estudo teve como objetivo avaliar a relação entre os níveis séricos da Molécula-1 de lesão renal (KIM-1) e o CNP em pacientes com infarto agudo do miocárdio com supradesnivelamento do segmento ST (IAMCSST).

Métodos

Este estudo incluiu um total de 160 pacientes (113 homens e 47 mulheres; média de idade: 61,65 ± 12,14 anos) com diagnóstico de IAMCSST. Os pacientes foram divididos em dois grupos, o grupo reflow (GR) (n = 140) e o grupo no-reflow (GNR) (n = 20). Os pacientes foram acompanhados durante um ano. Um valor de p<0,05 foi considerado significativo.

Resultados

O CNP foi observado em 12,50% dos pacientes. O nível de KIM-1 sérico foi significativamente maior no GNR do que no GR (20,26 ± 7,32 vs. 13,45 ± 6,40, p<0,001). O índice de massa corporal (IMC) foi significativamente maior no GNR do que no GR (29,41 (28,48-31,23) vs. 27,56 (25,44-31,03), p=0,047). A frequência cardíaca (FC) foi significativamente menor no GNR do que no GR (61,6 ± 8,04 vs. 80,37 ± 14,61, p<0,001). O escore do European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) foi significativamente maior no GNR do que no GR (3,06 ± 2,22 vs. 2,36 ± 2,85, p=0,016). A incidência de AVC foi significativamente maior no GNR do que no GR (15% vs. 2,90%, p=0,013). O nível basal de KIM-1 (OR = 1,19, IC 95%: 1,07-1,34, p=0,002) e HR (OR = 0,784, IC 95%: 0,69-0,88, p<0,001) foram os preditores independentes de CNP.

Conclusão

Em conclusão, os níveis séricos basais de KIM-1 e a FC mais baixa estão independentemente associados com CNP em pacientes com IAMCSST, e o acidente vascular cerebral foi significativamente maior no GNR em um ano de seguimento. (Arq Bras Cardiol. 2021; 116(2):238-247)

Prevention of medical malpractice and disputes through analysis of lawsuits related to coronary angiography and intervention

BACKGROUND/AIMS

Possible fatal complications arising from coronary angiography (CAG), percutaneous coronary intervention (PCI), and coronary artery disease itself, are likely to cause medical disputes. Presenting the current status and reasons for judgments given in lawsuits related to CAG/PCI, this study aimed to identify ways to prevent unnecessary disputes and medical malpractice suits related to CAG/PCI through lawsuit analysis.

METHODS

A total of 13 cases (20 judgments) found in the Supreme Court of Korea's Written Judgment Management System from 1998 to 2017 were analyzed.

RESULTS

Coronary artery injury was the most common causative complication that led to lawsuits (n = 6, 46%). Six cases (46%) were ruled in favor of the plaintiff for violation of duty of care (n = 4) and duty of explanation (n = 2), respectively. Cases that violated duty of care included two errors in intra-procedure device manipulation, one in pre-procedure diagnosis, and one in management of post-procedure complication. Lack of explanation regarding the risk of complications was pointed out in both cases that violated duty of explanation. The average awarded amount for the damages was 114,436,064 Korean won.

CONCLUSION

Physicians need not fear unfair judgments so long as they follow standard of care because the Court consistently looked at the probability, the foreseeability, and the evidence. Therefore, maintaining standard of care is important. Besides, specific, detailed, and comprehensible explanations, including the risk of complications in addition to the necessity of procedures, are important to ensure the patient clearly understands the possible risk of adverse outcomes.

A Practical Approach to the Management of Complications During Percutaneous Coronary Intervention

Percutaneous coronary intervention relieves symptoms in patients with chronic ischemic heart disease resistant to optimal medical therapy and alters the natural history of acute coronary syndromes. However, adverse procedural outcomes may occur during the intervention. Knowledge of possible complications and their timely management are essential for the practicing cardiologist and can be life-saving for the patient. In this review, the authors summarize potential complications of percutaneous coronary intervention focusing on their practical management.

Assessing and managing coronary microcirculation dysfunction in acute ST-segment elevation myocardial infarction

INTRODUCTION

Microvascular dysfunction in the setting of acute ST-segment elevation myocardial infarction (STEMI) is an indicator of poor long-term prognosis. Prompt assessment and pharmacological or procedural therapy (prophylactic or post onset of dysfunction) may improve outcomes in STEMI post-primary percutaneous intervention. Areas covered: The aim of this review is to provide a comprehensive analysis of the evidence available about the assessment and management of coronary microcirculatory injury/dysfunction in STEMI. We also aim to elucidate the possible strategies that could be applied in clinical practice to support the application of already available or novel therapeutic strategies for the prevention and management of microvascular impairment. Expert commentary: There are multiple established methods in assessing microvascular dysfunction, both non-invasively and invasively. Invasive physiological measurements allow real-time assessment of microvascular dysfunction and have prognostic cut-off values. Multiple therapeutic modalities exist for both preventing and treating microvascular dysfunction. These can be either pharmacological or mechanical, and there is no algorithm to guide if, how and when to apply them. Future research into both procedural and pharmacological therapy guided by physiological measurements is needed, with the aim of recognizing high-risk patients who would benefit from therapy.

A review of strategies for infarct size reduction during acute myocardial infarction

Advances in medical and interventional therapy over the last few decades have revolutionized the treatment of acute myocardial infarction. Despite the ability to restore epicardial coronary artery patency promptly through percutaneous coronary intervention, tissue level damage may continue. The reported 30-day mortality after all acute coronary syndromes is 2 to 3%, and around 5% following myocardial infarction. Post-infarct complications such as heart failure continue to be a major contributor to cardiovascular morbidity and mortality. Inadequate microvascular reperfusion leads to worse clinical outcomes and potentially strategies to reduce infarct size during periods of ischemia-reperfusion can improve outcomes. Many strategies have been tested, but no single strategy alone has shown a consistent result or benefit in large scale randomised clinical trials. Herein, we review the historical efforts, current strategies, and potential novel concepts that may improve myocardial protection and reduce infarct size.

Kounis syndrome with Samter-Beer triad treated with intracoronary adrenaline

Kounis syndrome is a well-described clinical condition characterized by the simultaneous occurrence of chest pain and an allergic reaction accompanied by clinical and laboratory findings of angina caused by inflammatory mediators released during an allergic insult. We present the case of a 50-year-old male with the Samter-Beer triad of asthma, nasal polyps, and salicylate intolerance with an ST elevation myocardial infarction complicated with cardiac arrest due to multi-vessel coronary artery spasm secondary to aspirin anaphylaxis. Adrenaline is recommended during anaphylaxis but is controversial in Kounis syndrome as it may worsen coronary spasm. We report the use of intracoronary adrenaline in successfully reversing coronary artery spasm in this hemodynamically unstable patient.

Intracoronary epinephrine in the treatment of refractory no-reflow after primary percutaneous coronary intervention: a retrospective study

Background

Despite the advances in medical and interventional treatment modalities, some patients develop epicardial coronary artery reperfusion but not myocardial reperfusion after primary percutaneous coronary intervention (PCI), known as no-reflow. The goal of this study was to evaluate the safety and efficacy of intracoronary epinephrine in reversing refractory no-reflow during primary PCI.

Methods

A total of 248 consecutive STEMI patients who had undergone primary PCI were retrospectively evaluated. Among those, 12 patients which received intracoronary epinephrine to treat a refractory no-reflow phenomenon were evaluated. Refractory no-reflow was defined as persistent TIMI flow grade (TFG) ≤2 despite intracoronary administration of at least one other pharmacologic intervention. TFG, TIMI frame count (TFC), and TIMI myocardial perfusion grade (TMPG) were recorded before and after intracoronary epinephrine administration.

Results

A mean of 333 ± 123 mcg of intracoronary epinephrine was administered. No-reflow was successfully reversed with complete restoration of TIMI 3 flow in 9 of 12 patients (75%). TFG improved from 1.33 ± 0.49 prior to epinephrine to 2.66 ± 0.65 after the treatment (p < 0.001). There was an improvement in coronary flow of at least one TFG in 11 (93%) patients, two TFG in 5 (42%) cases. TFC decreased from 56 ± 10 at the time of no-reflow to 19 ± 11 (p < 0.001). A reduction of TMPG from 0.83 ± 0.71 to 2.58 ± 0.66 was detected after epinephrine bolus (p < 0.001). Epinephrine administration was well tolerated without serious adverse hemodynamic or chronotropic effects. Intracoronary epinephrine resulted in significant but tolerable increase in heart rate (68 ± 13 to 95 ± 16 beats/min; p < 0.001) and systolic blood pressure (94 ± 18 to 140 ± 20; p < 0.001). Hypotension associated with no-reflow developed in 5 (42%) patients. During the procedure, intra-aortic balloon pump counterpulsation was required in two (17%) patients, transvenous pacing in 2 (17%) cases, and both intra-aortic balloon counterpulsation and transvenous pacing in one (8%) patients. One patient (8%) died despite all therapeutic measures.

Conclusion

Intracoronary epinephrine may become an effective alternative in patients suffering refractory no-reflow following primary PCI.

The REFLO-STEMI trial comparing intracoronary adenosine, sodium nitroprusside and standard therapy for the attenuation of infarct size and microvascular obstruction during primary percutaneous coronary intervention: study protocol for a randomised controlled trial

BACKGROUND

Microvascular obstruction (MVO) secondary to ischaemic-reperfusion injury is an important but underappreciated determinant of short- and longer-term outcome following percutaneous coronary intervention (PCI) treatment of ST-elevation myocardial infarction (STEMI). Several small studies have demonstrated a reduction in the degree of MVO utilising a variety of vasoactive agents, with adenosine and sodium nitroprusside (SNP) being most evaluated. However, the evidence base remains weak as the trials have had variable endpoints, differing drug doses and delivery. As such, the results regarding benefit are conflicting.

METHODS

The REperfusion Facilitated by LOcal adjunctive therapy in STEMI (REFLO-STEMI) trial is a multicentre, prospective, randomised, controlled, open label, study with blinded endpoint analysis: Patients presenting within 6 h of onset of STEMI and undergoing planned primary PCI (P-PCI) with TIMI 0/1 flow in the infarct-related artery (IRA) and no significant bystander coronary artery disease on angiography, are randomised into one of three groups: PCI with adjunctive pharmacotherapy (intracoronary adenosine or SNP) or control (standard PCI). All receive Bivalirudin anticoagulation and thrombus aspiration. The primary outcome is infarct size (IS) (determined as a percentage of total left ventricular mass) measured by cardiac magnetic resonance imaging (CMRI) undertaken at 48 to 72 h post P-PCI. Secondary outcome measures include MVO (hypoenhancement within infarct core) on CMRI, angiographic markers of microvascular perfusion and MACE during 1-month follow-up. The study aims to recruit 240 patients (powered at 80% to detect a 5% absolute reduction in IS).

DISCUSSION

The REFLO-STEMI study has been designed to address the weaknesses of previous trials, which have collectively failed to demonstrate whether adjunctive pharmacotherapy with adenosine and/or SNP can reduce measures of myocardial injury (infarct size and MVO) and improve clinical outcome, despite good basic evidence that they have the potential to attenuate this process. The REFLO-STEMI study will be the most scientifically robust trial to date evaluating whether adjunctive therapy (intracoronary adenosine or SNP following thrombus aspiration) reduces CMRI measured IS and MVO in patients undergoing P-PCI within 6 h of onset of STEMI.

TRIAL REGISTRATION

Trial registered 20th November 2012: ClinicalTrials.gov Identifier NCT01747174.

Usefulness of Intracoronary Epinephrine in Severe Hypotension during Percutaneous Coronary Interventions

Background and Objectives

Life-threatening hypotension during percutaneous coronary interventions (PCI) is devastating for the patient and is associated with fatal adverse outcomes. The aim of our study was to assess the usefulness of intracoronary epinephrine in severe hypotension unresponsive to other measures during PCI.

Subjects and Methods

We analyzed the Pusan National University Yangsan hospital cardiac catheterization laboratory database to identify patients who underwent PCI from December 2008 to July 2012. The outcomes were changes of blood pressure (BP) and heart rate (HR) before and after intracoronary epinephrine and in-hospital mortality.

Results

A total of 30 patients who were initially stable and received intracoronary epinephrine for severe hypotension during PCI were included. Following administration of intracoronary epinephrine (dose 181±24.8 microgram), systolic and diastolic BP (from 53.8±13.0 mm Hg up to 112.8±21.2 mm Hg, from 35±7.6 mm Hg up to 70.6±12.7 mm Hg, respectively) and HR (from 39.4±5.1 beats/min up to 96.8±29.3 beats/min) were increased. Additionally, 21 patients (70%) showed hemodynamically acceptable responses to intracoronary epinephrine without the intraaortic balloon pump and temporary pacemaker during the PCI. In-hospital mortality was 17% (n=5).

Conclusion

Although our study was small, intracoronary epinephrine was found to be well tolerated and resulted in prompt and successful recovery from severe hypotension in most patients when other measures were ineffective. Intracoronary epinephrine could be a safe and useful measure in patients developing severe hypotension during PCI.

Complications of coronary intervention: device embolisation, no-reflow, air embolism

The introduction of drug-eluting stents, better equipment, stronger antiplatelet drugs, and higher levels of operator experience has led to markedly improved patency rates for complex percutaneous coronary interventions (PCIs). The evolving techniques of contemporary PCI have been unable to completely eliminate complications. However, rigorous preventive measures pre-empt the appearance of complications. During traversal of severely diseased coronary arteries and manipulating equipment, particularly devices with detachable components, the opportunity for loss or embolisation of material in the coronary circulation presents itself. Device embolisation is associated with periprocedural myocardial infarction and emergent referral to surgery, particularly if the device is not retrieved. The coronary no-reflow phenomenon is a feared complication of PCI. It is associated with a worse prognosis and has been shown to be an independent predictor of death, myocardial infarction and impaired left ventricular function. Air embolism can be prevented by flushing of catheters during equipment exchanges.

Prevention and treatment of microvascular obstruction-related myocardial injury and coronary no-reflow following percutaneous coronary intervention: a systematic approach

Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed "no-reflow." Microvascular obstruction can be broadly categorized according to the duration of myocardial ischemia preceding PCI. In "interventional MVO" (e.g., elective PCI), obstruction typically involves myocardium that was not exposed to acute ischemia before PCI. Conversely "reperfusion MVO" (e.g., primary PCI for acute myocardial infarction) occurs within a myocardial territory that was ischemic before the coronary intervention. Interventional and reperfusion MVO have distinct pathophysiological mechanisms and may require individualized therapeutic approaches. Interventional MVO is triggered predominantly by downstream embolization of atherosclerotic material from the epicardial vessel wall into the distal microvasculature. Reperfusion MVO results from both distal embolization and ischemia-reperfusion injury within the subtended ischemic tissue. Management of MVO and no-reflow may be targeted at different levels: the epicardial artery, microvasculature, and tissue. The aim of the present report is to advocate a systematic approach to prevention and treatment of MVO in different clinical settings. Randomized clinical trials have studied strategies for prevention of MVO and no-reflow; however, the efficacy of measures for reversing MVO once no-reflow has been demonstrated angiographically is unclear. New approaches for prevention and treatment of MVO will require a better understanding of intracellular cardioprotective pathways such as the blockade of the mitochondrial permeability transition pore.

The pathogenesis and treatment of no-reflow occurring during percutaneous coronary intervention

No-reflow is one of the major causes of postinterventional rise of cardiac enzyme and myocardial infarction (MI). This complication is associated with substantial morbidity and mortality after percutaneous coronary intervention (PCI). During and after a no-reflow episode, the patient can suffer from severe chest pain, hypotension, bradycardia, hemodynamic collapse, MI, congestive heart failure, and death. Every effort should be taken to reduce the incidence of this complication. The distal embolic protection device has been shown to decrease this risk in saphenous vein graft (SVG) interventions but not in native coronaries. On the other hand, the use of glycoprotein IIb/IIIa receptor antagonists have been effective in reducing the occurrence of no-reflow during PCI of native coronaries but not during SVG interventions. The treatment of no-reflow is based on the intracoronary administrations of medications that induce maximal vasodilatation in small distal coronary vasculature. The most commonly used drugs in this setting are adenosine, nitroprusside, and verapamil. The goal of this study was to review the pathogenesis and treatment of no-reflow in patients undergoing PCI.

Management of 'no-reflow' complicating reperfusion therapy

No-reflow phenomenon, defined as inadequate myocardial perfusion of the adequately dilated target vessel without evidence of angiographic mechanical obstruction. It is a multifactorial, well-recognised, secondary phenomenon following reperfusion therapy such as thrombolysis or percutaneous coronary interventions (PCI). The pathophysiological mechanisms leading to the no-reflow state are incompletely understood. Embolization of the atheromatous material to the distal vasculature and intense arteriole vasospasm caused by microembolization of platelet-rich thrombi that release vasoactive agents resulting in microvascular obstructions are likely mechanisms. Current prophylaxis and management strategies are derived from limited clinical data. Intracoronary verapamil, adenosine and nitroprusside have been most frequently studied and administered for angiographic no-reflow during PCI for acute myocardial infarction or saphenous vein graft (SVG) lesions and have been shown to improve epicardial flow and microvascular perfusion. The use of distal embolic protection devices in SVG interventions also provide microvascular protection and improve clinical outcomes. However, by far the most important measures are prevention and anticipation during PCI as once no-reflow established, complete reversal of the situation may not be possible.

Percutaneous coronary intervention and the no-reflow phenomenon

No-reflow during percutaneous coronary intervention (PCI) is observed most commonly during saphenous vein graft intervention, rotational atherectomy and primary PCI for acute ST-elevation myocardial infarction. The contributions of distal embolization and ischemia/reperfusion injury to the pathogenesis of no-reflow vary in these settings, as does prevention and management. Prevention of no-reflow in these high-risk groups is the best treatment strategy, employing antiplatelet agents, vasodilators and/or mechanical devices to prevent distal embolization. Once mechanical factors are excluded as a cause for reduced epicardial flow, the treatment of established no-reflow is mainly pharmacologic, since the obstruction occurs at the level of the microvasculature. Compared with patients in whom no-reflow is transient, refractory no-reflow is associated with a markedly increased risk of 30-day mortality.

Efficacy of intracoronary nicardipine in the treatment of no-reflow during percutaneous coronary intervention

OBJECTIVES

The goal of this study was to evaluate the safety and efficacy of nicardipine in reversing no-reflow during percutaneous coronary intervention (PCI).

BACKGROUND

No-reflow is a common complication of PCI in patients with acute coronary syndromes or venous bypass graft disease. Although nicardipine has an attractive pharmacological profile and has been used clinically to treat no-reflow, there is a paucity of published data regarding its effectiveness in this setting.

METHODS

We conducted a retrospective analysis of 72 consecutive patients who received intracoronary nicardipine to reverse no-reflow during coronary intervention. Qualitative TIMI flow grade and quantitative TIMI frame count methods were used to assess the efficacy of nicardipine.

RESULTS

A mean of 460 +/- 360 mcg of intracoronary nicardipine was used. No-reflow was successfully reversed with complete restoration of TIMI 3 flow in 71 of 72 patients (98.6%). TIMI flow grade improved from 1.65 +/- 0.53 prior to nicardipine to 2.97 +/- 0.24 after treatment (P < 0.001). TIMI frame count decreased from 57 +/- 40 at the time of no-reflow to 15 +/- 12 after nicardipine administration (P < 0.001). Nicardipine therapy was well tolerated without adverse hemodynamic or chronotropic effects.

CONCLUSIONS

In this largest series to date, intracoronary nicardipine was demonstrated to be a safe and highly effective pharmacological agent to reverse no-reflow during PCI.

Treatment of slow/no-reflow phenomenon with intracoronary nitroprusside injection in primary coronary intervention for acute myocardial infarction

Slow/no-reflow phenomenon is a serious problem complicating primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) and is associated with a poor prognosis. From January 2002 to November 2002, 11 of the 70 consecutive patients with ST elevation AMI who were subjected to primary PCI using balloon angioplasty and/or stenting developed slow/no-reflow phenomenon (TIMI 1 flow in 2, TIMI 2 in 8, and TIMI 2.5 in 1). They were 10 men and 1 woman, aged 64 +/- 11 years (range, 46-81). The culprit vessels were six in the left anterior descending coronary artery, three in the right coronary artery, one in the left circumflex coronary artery, and one in saphenous vein graft. Multiple bolus doses (100 microg) of nitroprusside were injected into the index artery through the guiding catheter using a 3 ml syringe until the TIMI flow grade improved by at least one grade or the systolic pressure decline below 80 mm Hg (one patient). The total drug dose varied from 100 to 700 microg. Following the drug treatment, angiographic TIMI flow grade improved by at least one grade in 9 (82%) of the 11 patients (P = 0.007). The TIMI frame counts significantly decreased from 36 +/- 17 frame counts to 16 +/- 11 frame counts (P = 0.012). All patients were discharged without major adverse cardiovascular events. Intracoronary bolus injection of nitroprusside using a 3 ml syringe appears to be a feasible, safe, and effective technique for the management of slow/no-reflow phenomenon complicating primary PCI.

Incidence and Management of "No-Reflow" Following Percutaneous Coronary Interventions

No-reflow is a complex condition associated with inadequate myocardial perfusion of the coronary artery in the absence of epicardial obstruction. It can occur in several settings, including percutaneous coronary intervention, especially in complex thrombotic lesions of native arteries and vein grafts and in primary angioplasty. The causes of no-reflow are not completely understood, and current treatments consist of intracoronary vasodilators, antithrombotic therapies, and mechanical devices (including aspiration thrombectomy catheters and embolic protection devices).

Coronary no-reflow phenomenon

No-reflow occurs in up to one third of patients with acute myocardial infarction during acute percutaneous intervention, and occasionally during elective interventions, particularly vein graft intervention. Multiple intracoronary medications will restore flow in most cases. We begin with 100 to 1000 mg of nitroprusside, verapamil, or adenosine at a similar dosage. We give it at 100-mg increments at high velocity. We inject it distally in the epicardial artery to avoid any systemic effect, and we do it through an intracoronary perfusion catheter. At times, we use prophylactic injections (prior to balloon inflation), particularly in vein graft intervention. Most of these strategies are not formally approved for treating no-reflow. However, reversing this condition with restoration of normal coronary flow is essential for an improved left ventricular function and a better cardiac outcome.

The no-reflow phenomenon in coronary arteries

No reflow occurs when there is inadequate myocardial perfusion of a given segment of the coronary circulation without evidence of epicardial vessel obstruction. It is a rare but clinically significant condition associated with myocardial infarction and coronary interventions. Diagnosis is usually based on clinical signs of myocardial ischemia (symptoms and/or ECG changes) combined with coronary angiography. Management can be difficult and primarily consists of intracoronary administration of vasodilators. One interesting etiology is thromboembolism and this has become the focus for new potential treatments, including distal embolic protection devices.

Coronary Hyperemic Dose Responses of Intracoronary Sodium Nitroprusside

Background— Sodium nitroprusside is one of several agents considered effective for treating the no-reflow phenomenon during acute coronary interventions. However, the coronary hyperemic dose responses and systemic hemodynamic effects of intracoronary nitroprusside have yet to be determined in humans. The purpose of this study was to compare the hyperemic and hemodynamic responses of intracoronary nitroprusside to intracoronary adenosine in patients during cardiac catheterization with angiographically normal anterior descending arteries.

Methods and Results— In 21 patients, coronary blood flow velocity (0.014-inch Doppler flow wire), heart rate, and blood pressure were measured in unobstructed left anterior descending coronary arteries at rest, after intracoronary adenosine (30- to 50-μg boluses), and after 3 serial doses (0.3-, 0.6-, and 0.9-μg/kg boluses) of intracoronary nitroprusside. Coronary reserve was calculated as hyperemia/basal coronary flow velocity. In an additional 9 patients with intermediate stenoses (53±7%), 14 fractional flow reserve (FFR) measurements (using 0.014-inch pressure wire) were performed with both intracoronary adenosine and nitroprusside (0.6 μg/kg). Intracoronary nitroprusside produced equivalent coronary hyperemia with a longer duration (≈25%) compared with intracoronary adenosine. Intracoronary nitroprusside (0.9 μg/kg) decreased systolic blood pressure by <20%, with minimal change in heart rate, whereas intracoronary adenosine had no effect on these parameters. FFR measurements with intracoronary nitroprusside were identical to those obtained with intracoronary adenosine ( r =0.97).

Conclusions— Compared with adenosine, intracoronary nitroprusside produces an equivalent but more prolonged coronary hyperemic response in normal coronary arteries. Intracoronary nitroprusside, in doses commonly used for the treatment of the no-reflow phenomenon, can produce sustained coronary hyperemia without detrimental systemic hemodynamics. On the basis of FFR measurements compared with adenosine, sodium nitroprusside also appears to be a suitable hyperemic stimulus for coronary physiological measurements.